The present invention relates to a novel olefin polymerization catalyst and a process for olefin polymerization using the olefin polymerization catalyst.
xe2x80x9cKaminsky catalystsxe2x80x9d are well known as olefin polymerization catalysts. The Kaminsky catalysts exhibit extremely high polymerization activity, and by the use of them, polymers of narrow molecular weight distribution can be obtained.
Transition metal compounds known as employable for the Kaminsky catalysts are, for example, bis(cyclopentadienyl)zirconium dichloride (see Japanese Patent Laid-Open Publication No. 19309/1983) and ethylenebis(4,5,6,7-tetrahydroindenyl)zirconium dichloride (see Japanese Patent Laid-Open Publication No. 130314/1986). It is also known that the olefin polymerization activity and the properties of the resulting polyolefins greatly vary when different transition metal compounds are used in the polymerization.
Recently, an olefin polymerization catalyst comprising a titanium amide compound having a titanium-nitrogen bond and an aluminoxane has been proposed as a novel olefin polymerization catalyst in, for example, Japanese Patent Laid-Open Publication No. 245713/1996.
Further, an organometallic complex having a metal of Group 4 of the periodic table, which contains a bis(borylamido) ligand represented by (Mes2BNCH2CH2NBMes2)xe2x88x922, is described in xe2x80x9cOrganometallicsxe2x80x9d, 1996, 15, 562-569. It is also described that this complex slightly exhibits ethylene polymerization activity.
By the way, polyolefins generally have excellent mechanical properties, so that they are used in many fields such as fields of various molded products. With the diversification of requirements for the properties of the polyolefins, polyolefins of various properties have been desired in recent years. Moreover, increase of productivity has been also desired.
Under such circumstances as mentioned above, there has been desired development of olefin polymerization catalysts exhibiting excellent olefin polymerization activity and capable of producing polyolefins of excellent properties.
The olefin polymerization catalyst according to the invention comprises:
(A) a transition metal imine compound represented by the following formula (1-a) or (I-b), and
(B) at least one compound selected from:
(B-1) an organometallic compound,
(B-2) an organoaluminum oxy-compound, and
(B-3) a compound which reacts with the transition metal imine compound (A) to form an ion pair; 
xe2x80x83wherein M is a transition metal atom of Group 8 to Group 11 of the periodic table,.
R1 to R4 may be the same or different and are each a hydrogen atom, a halogen atom, a halogenated hydrocarbon group, a hydrocarbon group, a heterocyclic compound residual group, an oxygen-containing group, a nitrogen-containing group, a boron-containing group, a sulfur-containing group, a phosphorus-containing group, a silicon-containing group, a germanium-containing group, a tin-containing group or the like,
R5 and R6 may be the same or different and are each a halogen atom, a halogenated hydrocarbon group, a hydrocarbon group, a heterocyclic compound residual group, an oxygen-containing group, a nitrogen-containing group, a boron-containing group, a sulfur-containing group, a phosphorus-containing group, a silicon-containing group, a germanium-containing group, a tin-containing group or the like,
R1 and R5 may be bonded to each other to form a ring, R2 and R6 may be bonded to each other to form a ring, R1 and R3 may be bonded to each other to form a ring, and R2 and R4 may be bonded to each other to form a ring,
m is an integer of 0 to 2,
n is an integer of 0 or 2,
each A may be the same or different and is an atom of Group 13 to Group 16 of the periodic table,
E is a substituent group having at least one element selected from carbon, hydrogen, oxygen, halogen, nitrogen, sulfur, phosphorus, boron and silicon, and when plural groups indicated by E are present, they may be the same or different, and two or more groups indicated by E may be bonded to each other to form a ring,
p is a number satisfying a valence of M,
X is a hydrogen atom, a halogen atom, a hydrocarbon group of 1 to 20 carbon atoms, a halogenated hydrocarbon group of 1 to 20 carbon atoms, an oxygen-containing group, a sulfur-containing group, a silicon-containing group or the like, and when n is 2 or greater, plural groups indicated by X may be the same or different, and
Y is an atom of Group 15 of the periodic table.
A preferred example of the transition metal imine compound represented by the formula (I-a) or (I-b) is a transition metal imine compound represented by the following formula (II-a) or (II-b): 
wherein M is a transition metal atom of Group 8 to Group 11 of the periodic table,
R7 to R10 may be the same or different and are each a hydrogen atom, a halogen atom, a hydrocarbon group, a halogenated hydrocarbon group, a heterocyclic compound residual group, a hydrocarbon-substituted silyl group, a hydrocarbon-substituted siloxy group, an alkoxy group, an alkylthio group, an aryloxy group, an arylthio group, an acyl group, an ester group, a thioester group, an amido group, an imido group, an amino group, an imino group, a sulfonate ester group, a sulfonamido group, a cyano group, a nitro group, a carboxyl group, a sulfonyl group, a mercapto group, a hydroxyl group or the like,
each R11 may be the same or different and is a halogen atom, a hydrocarbon group, a halogenated hydrocarbon group, a heterocyclic compound residual group, a hydrocarbon-substituted silyl group, a hydrocarbon-substituted siloxy group, an alkoxy group, an alkylthio group, an aryloxy group, an arylthio group, an acyl group, an ester group, a thioester group, an amido group, an imido group, an amino group, an imino group, a sulfonate ester group, a sulfonamido group, a cyano group, a nitro group, a carboxyl group, a sulfonyl group, a mercapto group, a hydroxyl group or the like,
R7 and R9 may be bonded to each other to form a ring, R8 and R10 may be bonded to each other to form a ring, and R8 and R10 may be bonded to each other to form a ring,
R12 to R16 may be the same or different, they are each a hydrogen atom, a halogen atom, a hydrocarbon group, a halogenated hydrocarbon group, a heterocyclic compound residual group, a hydrocarbon-substituted silyl group, a hydrocarbon-substituted siloxy group, an alkoxy group, an alkylthio group, an aryloxy group, an arylthio group, an acyl group, an ester group, a thioester group, an amido group, an imido group, an amino group, an imino group, a sulfonate ester group, a sulfonamido group, a cyano group, a nitro group, a carboxyl group, a sulfonyl group, a mercapto group, a hydroxyl group or the like, at least one of R12 to R16 is a group other than a hydrogen atom, and two or more of the groups indicated by R12 to R16 may be bonded to each other to form a ring,
m is an integer of 0 to 2,
n is an integer of 0 or 2,
each A may be the same or different and is an atom of Group 13 to Group 16 of the periodic table,
E is a substituent group having at least one element selected from carbon, hydrogen, oxygen, halogen, nitrogen, sulfur, phosphorus, boron and silicon, and when plural groups indicated by E are present, they may be the same or different, and two or more groups indicated by E may be bonded to each other to form a ring,
p is a number satisfying a valence of M,
X is a hydrogen atom, a halogen atom, a hydrocarbon group of 1 to 20 carbon atoms, a halogenated hydrocarbon group of 1 to 20 carbon atoms, an oxygen-containing group, a sulfur-containing group, a silicon-containing group or the like, and when n is 2 or greater, plural groups indicated by X may be the same or different, and
Y is an atom of Group 15 of the periodic table.
Another preferred example of the transition metal imine compound represented by the formula (I-a) or (I-b) is a transition metal imine compound represented by the following formula (III-a) or (III-b): 
wherein M is a transition metal atom of Group 8 to Group 11 of the periodic table,
R17 to R20 may be the same or different and are each a hydrogen atom, a halogen atom, a hydrocarbon group, a halogenated hydrocarbon group, a heterocyclic compound residual group, a hydrocarbon-substituted silyl group, a hydrocarbon-substituted siloxy group, an alkoxy group, an alkylthio group, an aryloxy group, an arylthio group, an acyl group, an ester group, a thioester group, an amido group, an imido group, an amino group, an imino group, a sulfonate ester group, a sulfonamido group, a cyano group, a nitro group, a carboxyl group, a sulfonyl group, a mercapto group, a hydroxyl group or the like,
R17 and R19 may be bonded to each other to form a ring, and R18 and R20 may be bonded to each other to form a ring,
R21 to R30 may be the same or different and are each a hydrogen atom, a halogen atom, a hydrocarbon group, a halogenated hydrocarbon group, a heterocyclic compound residual group, a hydrocarbon-substituted silyl group, a hydrocarbon-substituted siloxy group, an alkoxy group, an alkylthio group, an aryloxy group, an arylthio group, an acyl group, an ester group, a thioester group, an amido group, an imido group, an amino group, an imino group, a sulfonate ester group, a sulfonamido group, a cyano group, a nitro group, a carboxyl group, a sulfonyl group, a mercapto group, a hydroxyl group or the like,
at least one of R21 to R25 is a group other than a hydrogen atom, at least one of R26 to R30 is a group other than a hydrogen atom, two or more of the groups indicated by R21 to R25 may be bonded to each other to form a ring, and two or more of the groups indicated by R26 to R30 may be bonded to each other to form a ring,
m is an integer of 0 to 2,
n is an integer of 0 or 2,
each A may be the same or different and is an atom of Group 13 to Group 16 of the periodic table,
E is a substituent group having at least one element selected from carbon, hydrogen, oxygen, halogen, nitrogen, sulfur, phosphorus, boron and silicon, and when plural groups indicated by E are present, they may be the same or different, and two or more groups indicated by E may be bonded to each other to form a ring,
p is a number satisfying a valence of M,
X is a hydrogen atom, a halogen atom, a hydrocarbon group of 1 to 20 carbon atoms, a halogenated hydrocarbon group of 1 to 20 carbon atoms, an oxygen-containing group, a sulfur-containing group, a silicon-containing group or the like, and when n is 2 or greater, plural groups indicated by X may be the same or different, and
Y is an atom of Group 15 of the periodic table.
The process for olefin polymerization according to the invention comprises polymerizing or copolymerizing an olefin in the presence of the above-mentioned olefin polymerization catalyst.